Surface configuration of an engine



FIG. 1 is a left perspective view of a surface configuration of an engine according to my novel design;

FIG. 2 is a right perspective view of the surface configuration of an engine according to my novel design;

FIG. 3 is a front elevated perspective view of the surface configuration of an engine according to my novel design; and,

FIG. 4 is a front view of the surface configuration of an engine according to my novel design.

The broken lines included in the drawings depict environment and are not part of the claimed design. 

The ornamental design for a surface configuration of an engine, as shown and described. 